(a) Field
The described technology relates generally to a method and an apparatus for interference aware communications, and more particularly, to a method and an apparatus for interference aware communications in a wireless local area network (WLAN).
(b) Description of the Related Art
A WLAN is being standardized by the IEEE (Institute of Electrical and Electronics Engineers) Part 11 under the name of “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications.”
After an original standard was published in 1999, new version standards are continuously published by amendments. The IEEE standard 802.11a (IEEE Std 802.11a-1999) supporting 2.4 GHz band was published in 1999, the IEEE standard 802.11b (IEEE Std 802.11b-1999) supporting 5 GHz band was published in 1999, and the IEEE standard 802.11g (IEEE Std 802.11g-2003) supporting 5 GHz band was published in 2003. These standards are called legacy. Subsequently, the IEEE standard 802.11n (IEEE Std 802.11n-2009) for enhancements for higher throughput (HT) was published in 2009, and the IEEE standard 802.11 ac (IEEE 802.11 ac-2013) for enhancements for very high throughput (VHT) was published in 2013. Recently, a high efficiency (HE) WLAN for enhancing the system throughput in high density scenarios is being developed by the IEEE 802.11ax task group.
Since a wireless local area network (WLAN) uses a non-licensed frequency bandwidth, various devices present in the WLAN cause interference with each other. To avoid collisions with other devices, the WLAN device may uses a CSMA/CA (carrier sense multiple access/collision avoidance) scheme. The WLAN device may transmit a RTS (request to send)/CTS (clear to send) frame to inform neighbor devices of a channel occupation duration. The neighbor devices may set a network allocation vector (NAV) based on a duration field of the RTS/CTS frame and defer a medium access for the NAV duration. However, in dense networks overlapped a plurality of basic service sets (BSSs), if the NAV is set by the frames transmitted by the neighbor BSSs, a resource reused in the neighbor BSSs is reduced. A system throughput may be reduced.
In addition, the interference condition of a sender and a receiver in the dense networks may be unsymmetrical. In particular, to increase transmission opportunity by dynamically adjusting a clear channel assessment (CCA) level using a dynamic sensitivity control (DSC), an unsymmetrical interference condition may occur frequently. However the sender and the receiver are not aware of interference of the other party under the unsymmetrical interference condition. The system throughput may be reduced due to a frame loss by the interference.
The above information disclosed in this Background section is only for enhancement of understanding of the background and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.